Relay



Feb. 8, 1927. ,2 7

W. D. HAILES RELAY Filed Sept. 15. 1924 /Za/ M AT ORNEY Fig.1.

' type of relay,

Patented Feb. 8, 1927.

'- um rE-o STATES 1,617,247 PATENT OFF-tell.

WILLIAM D. Harms, or nocrrnsr'na, new onir, assrelvon'roennnnat RAILWAY SIGNAL coMrANY, or ROCHESTER; NEW YORK.

RELAY.

Application filed September 15, 1924. Serial No. 737,858.

I This invention relates to a polyphase alternating current relay of the vane type, and more specifically concerns; improvement 1n the operating characteristics and; the provi- .sion of an electrical centering means for this Relays of the polyphase type are used to control circuits for electrical apparatus and are usually designed to selectively operate a number otcontacts' by the movement of a rotor or vane which derives its torque from .the magnetic fields produced by two field windings carrying alternating currents which aredisplaced in phase relation. WVhen either one or both of the field windings are :de-energized, the moving element or vane is moved to a central or neutral position by ;,means of suitable counterweighting means or springs. The load torque from the neu tral to the extreme energized position of a relay of this type; first consists of the torque required to overcome the counterweighting,

Vandthen, as the contact fingers are compressed, the torque, increases to a maximum value, resulting in a load torque which has a low initial value but it increases rapidly as themov'ing element is swung-to its extreme energized position, In the usual type of vane relay, the torque produced by the en so ergization of the relay windings is of a substantiallyconstant value for all angularpositions; of the vane; This is undesirable for the reason that the relay torque must be reduced toavalue lower than the initial value .r of theload torque before the relay will assume its final de-energized position, and

therefore acomplete drop away of the relay v cannot'be effected by partial reduction of the energy suppliedto one of its windings. It is found that when one of the relay windings is de-energized and the other winding remains energized, the flux generated by :the energized winding produces a magnetic dragon the, vane or rotor, tending to make the rotor slow n ts movement to theneutral or de-energized position. It sometimes becomes desirable to supply one of the relay windingswith a large amount of energy "from. a local source so that a small amount of controlled energy from some remote point may produce sufii cient torque to cause the a; relay to, operate- In the usual type of relay, when theco'ntrolled energy is cut off,

gtheniagnetic drag caused by the flux from the locally energized winding makes the and arranged to produce an electromagnetic centering torque, tending to swing the vane to its neutral position and tohold it in such position when either one of the relay windings alone is energized. It is also proposed to provide a relay having an operating torque which increases, rapidly as thevane moves to its extreme energized position, so providing a relay torque which corresponds as nearly as possible tothe 'counterweighting and contact load torque.

Other objects and advantages of the present invention will be pointed out or willbecome apparent in the description thereof.

Inthe drawings, Figurel represents adiagrammatic side view of a vane shaped according to this invention together with a simplified showing of the-contacts and contact operating means and a cross section of the fieldsti'ucture takenon the line 1 1 of Figure 2 and viewed in the direction of the arrows; I

c Fig. 2 is a horizontal section of the relay vane and field structure taken along the line on a plane passing" through the air gap and looking in the directionot the other field element. p j

Referring to Figures 1 and 2, the relay embodying the present invention comprises a vane l, secured to "a shaft 2, which is rotatably journaled in a suitable support, not

shown, in such a manner that the vane 1 may be rotatedor swung in a plane at right angles to the shaft 2.

p The shaft 2 is journal'ed in very light bear ngs, wh ch maybe ]ewel bearings of the well known type, so

that the vane may swing freely and with a minimum of friction. The vane 1 comprises a thin sheet of light electro-conductive material, preferably aluminum, and is of a shape shown in the drawings which differs from the ordinary circular type of vane principally in that a portion of the lower edge is cut away to form a flat side at 3 which is horizontal when the vane is in its neutral position as shown in Figure 1. The upper portion of the vane 1 is shaped so that the center of mass otthe vane is below the axis of rotation when the vane is in its neutral position. This shape of the vane may be used as a counterweight to bring the vane to its neutral posit-ion or additional counterweights may be used.

The field structure comprises thetwo laminated iron'cores 4 and 9, the core 4 having two legs terminating in the pole pieces 5 and 6 and carrying the two windings 7, and the core 9 having three legs terminating in the pole pieces 10, 11 and 12, the central leg carrying the winding 13 as clearly shown in Fig. 2. These cores 4 and 9 and the pole pieces 5, 6, 10, 11 and 12 are synnnetrically arranged with respa' ct to each other and with respect to'a vertical plane passing through the axis of rotation of the vane 1 and are so arranged with respect to each other that the faces of thepole pieces are parallel to the vane 1 and in close proximity thereto forming an air gap. The cores are so mounted that the vane 1 extends over a little more than halfiof the area of each of the pole pieces 5, 6, 10, 11 and 12 when the vane is in its neutral position.

Any suitable means may be used for opening and closing electrical circuits in ac cordance with the motion of the vane 1. For the purpose of illustration, a crank 14 has been shown, pinned to the shaft 2, andpivotally connected at its free end to the connecting rod 15. A carrier bar 16 is journaled on the pin 17 and is pivotally connected with the connecting rod 15 as shown. This carrier bar 16 is provided with insulating posts 18 to which are fastened the contact arms 19 provided with the spring contact fingers 20 terminating in the contact tips 21 which are adapted to engage the stationary contacts 22. The stationary contacts 22 and the contact tips 21 may be arranged to open and close various circuits at different positions of the vane, and in the specific arrangement shown, certain of the contacts are arranged to be closed when the vane 1 is in its neutral position, while others of the contacts are arranged to be closed when the vane is in one or the other of its extreme energized positions.

The torque for moving the vane 1 and thereby operating the contacts is produced by a shifting magnetic field in the air gap. The field windings 7 of the core 4 and the field winding 13 of the core 9 are supplied with separate alternating control currents which are displaced in phase relation, these currents being as nearly as possible in phase quadrature. The flux in the cores 4 and 9 resulting from these displaced alternating currents produce a field which shifts along the plane of the vane 1 and produces a torque in this vane in accordance with the well known laws of electro-magnetic induction, the direction of this torque being dependent upon the relation between the instantaneous polarity of the currents in the field windings 7 and 13. It is evident that the direction of movement of the vane 1 may be reversed by reversing the instantaneous polarity of the alternating current supplied to either the windings 7 or the windings 13, and that the de-energization of either one or both of these windings will result in a roduction of the torque in the relay vane.

Referring now more particularly to the electro-magnetic centering feature which constitutes in part the present invention, assume that the vane 1 is in its extreme energized position as shown by the dotted lines in Fig. 3, and that the winding 13 of the core 9 becomes de-energized while the winding 7 of the core 4 remains energized. Under these conditions an electro-magnetic force acts upon the vane 1, tending to center the vane in its neutral position. This action may be explained on the theory that a force corresponding to the well known blow-out force which accompanies an attempt to enter a sheet of electro-conductive material into a field comprising an alternating magnetic fiux, acts upon the vane 1. As the greatest area of the vane 1 is above the center of the pole pieces 5 and 6, the blow-out force produced by the flux from these poles will act to force the vane upward and out of their fields, the flux from the pole 5 tending to swing the vane 1 in a counter-clockwise direction, thus producing a couple about the shaft 2. As a larger area of the vane 1 is in the path of the fiux from the pole (3 than from the pole 5, the blow-out iorce produced by the pole 6 will predominate, and the vane 1 will be swung in a clockwise direction until the blow-out force produced by each pole exactly balances that produced by the other, which condition obviously exists only when equal areas of the two poles are covered by the vane. As the poles are arranged in a position symmetrical with respect to a vertical plane through the axis of rotation of the vane, it is obvious that the blow-out force just described centers the vane in its neutral position and tends to maintain it in that position, thus preventing a slow drop away action, a failure to drop away or a swinging back and forth and a momentary opening and closing of the relay contacts upon the de-energization of one of its windings. From an inspection of Fig. 4 it is evident that when the winding 7 is de-energized and the winding 13 remains energized a centering torque is produced in a manner identical with that described in connection with Fig.

' 3. The poles and 12 together with the twohalves of the pole 11' of the core 9 produce two opposing-'forcea-one of which will predominate until the vane assumes a position at which equal areas of the poles on ea'chjside of a; vertical plane through the axis of rotation are covered by the vane 1,

Which'position is the neutral position of -the-relay.

Another explanation of the, centeringac- 'tion"produ'ced' by theenergization of one relay-windingalone may be based upon the well knownprinciple that any electrical device tends to assume a position such that its losses are at a minim-um; In the "relay comprising the present invention, the variable 'lo'sses which exist Whenone winding alone is energi-zed'are mainly due to the eddyfcurrentldssesj 1n the vane 1-, and as these eddy-current l'ossesare a minimum when a m nimum area'of the'vane 1's in the path oi the alternating flux from such winding,

thatjis, whenfthe vane is in the neutral position, the vane tends-to assume such neutral position upon the energization of one of the relay windingsalone.

' The, centeri'n'gtorque produced when one of the relay windings alone is energized 1s a verydesirable feature m relay construction.

"As' hereifnbefore stated, it is often desirable int-rack relays to use alargeamount of energy on one o-fthe relay phase windings in""orderthat a small amount of controlled energy i-I'r'the other phase winding will produce suflieienttorque to actuate the contacts.

In the ordinary type of vanerelay, when the controlled energy is cut off, the relay assuines' its deenergized position very slowly due to th'e' magneto drag on the vane produed --by'-'the' flux from the heavily energi z'ed' windi-ng. In the relayof this invention, the flux fromthe heavily energ zed winding tends to center the vane rapidly upon thede-energi zation of the lightly energized winding, making the; relay quick-act-' ing' and doing away the necessity for powerful "counter-welghtingmeans.

fl .Ithas been observed in practice that in produced" in the relay when-one of thewindingsis energized alone. This torque causes the relay vane to creep; that is, tomove slow- 1y aw ay from its neutral position when only 'o'neof'the relay windings is energized, and

'droppi ngrromtne energized to the neutral 'position. In the type of vane relay con- 'structed aecordingtoth-is invention the electro-magnetie centering feature, which has been described above, overcomes this objectionable creeping action, as the relay vane is swung to and held in its neutral position by the energization of one of its windings alone, and the tendency of the vane is to remain in this neutral position until both relay windings are energized.

In polyphase relays of the vane type, the load torquedoes not maintain a constant value as the relay moves from its neutral to itsextreme energized position. The lo ad'at first consists of the counterweighting alone, and as the angle of rotation increases, the load torque is rapidly increased by the reaction ofth'e contact springs as; they are compressed. In the ordinary type of polyphasc vane relay, the relay torque, that is, the torque produced by the relay windings, is

substantially constant for all angular positions of the vane, and so must be large enough when the relay is started from its neutral position to overcome the maximum load torque which is encountered when the vane is in its extreme energized position. This results in the fact that an amount of energy must be supplied to the relay windings which is in excess-oi the amount required to move the vane through the first portion of its angle of rotation from the neutral to the extreme energized positions. In the relay of this invention, the fiat side or cutaway portion of thevane 1 results in a relay torque which increases in the same manner as the load torque which it must overcome. Since the torque produced increases as more conducting material is brought into the shifting magnetic field, and since when the relay is in its neutral position, a minimum area of the vane 1 is in the path-of the shifting flux field produced by "the field windings, a minimum' relay torque will be produced at this position, but

as the vane swings toward its energized position, the area of the van-e which is in the pathof the shifting field rapidly increases and the relay torque increases in proportion. It'is thus clear that the relation of the relay torque to the angular posi tion of the vane-corresponds to the relation of the load torque to the angular position of the vane, and hence a slight reduction in the energy supplied to the relay when in its ex-- treme energized position will result in a complete drop away of the vane to the neutralposition, whereas in the usual type of vane relay the relay torque mustbe reduced to a value lower than the lowest value in load torque before the vane will finally j assume its neutral position. may result in thelmproper opening of the.

neutral. contacts or. prevent the relay from It should be noted that the centering torque and the starting torque of the relay embodying the present invention are dependent upon the relativepositionsof the cut away portioirot the vane and the field structure, If the area of the pole pieces increased and thestarting torque decreased. is For this reason the relative positions of the vane and the field structure may be varied in order to adapt the relay to the particular operating conditions under which it is to be used.

As the present invention has been shown and described in connection with a rather specific form of relay it should be clearly understood that the principle involved in the device disclosed may be applied to any suitable type of relay, that any suitable form of mounting means, contacts or power transmitting means might be used and that many other modifications, additions and combinations could be made without departing from the spirit of the present invention.

What it is desired to secure by Letters Patent of the United States is 1. In an induction type alternating current relay, two separate magnetic structures having aligned pole pieces separated by an air gap, separately energized coils on said magnetic structures, and a vane ofconducting material movably supported in said air gap, said vane being so shaped that an alternating flux from one of said magnetic structures alone will cause said vane to move to and remain in a definite position{ 2. In an induction type of alternating current relay, a movable element comprising a vane of electro-conductive material, a field structure for moving said vane comprising two independently magnetized cores on opposite sides of said vane havingaligned pole pieces in close proximity to said vane, a winding on each of said cores, said field structure producing a shifting magnetic field cutting said vane when said windings are simultaneously energized by alternating currents which are displaced in phase relation, and said vane being so shaped that the magnetic field produced by one of said cores alone will cause said vane to move to and remain in a definite position relative to said cores.

3. In an induction type alternating current relay, a movable element comprising a vane of electro-conductive material, a field structure for moving said vane comprising two independently magnetized cores on opposite sides of said vane having aligned pole pieces in close proximity to said vane, said pole pieces being arranged symmetrically with respect to the axis of rotation of said vane, a winding oneach of said cores, said field structure producing a shifting magnetic field through said vane to move said vane from a neutral to an energized position when said windings are independently and simultaneously energized by alternating currents which are displaced in phase relation, said vane being so shaped as to he between a portion of the areas of said pole pieces only when said vane is in its neutral position, whereby the magnetic field from one of said cores alone will cause said vane to move to and remain in its neutral position.

l. In an alternating current relay of the induction type,a field structure comprising neutral position whereby the simultaneousenergization of said windings will produce a torque for moving'said vane to said energized position, which torque increases as said vane moves toward said energized position, and the energization of either of said windings alone will produce a torque for moving said vane to said neutral position.

5. In an alternating current relay of the induction type, a movably mounted vane of electro-conductive material, and electromagnetic means ii'or producing a shifting magnetic field cutting a portion of said vane for moving said vane in a given direction, said vane being shaped to intercept an increasing amount of said shifting magnetic field as said vane is moved in said given direction.

6. In an alternating current relay of the induction type, a rotatably mounted element comprising an imperi'orate vane of substantially semi-circular form having a fiat side, means for moving said vane comprising two sources of alternating magnetic flux displaced in phase relation, said sources of flux being symmetrically arranged with respect to a plane passing through the axis of rotation of said vane, whereby an alternating flux from one of said sources alone will produce a torque in said vane tending to turn said vane to a position at which said flat side is symmetrical with respect to said sources and to retain said vane in such position.

7. In an alternating current relay of the induction type, a movable element comprising a rotatably mounted imperiorate vane of electro-conductive material having a fiat side, and two separately energized field pieces having their poles arranged on opposite sides of said vane and symmetrical with respect to a plane passing through the axis ,of rotation of said vane, said poles being symmetrical with respect to said flat side for moving said-vane comprising two separately energized field pieces mounted on opposite sides of said vane and having pole pieces arranged to be covered by a portion of said vane, said flat side being arranged to cover equal partial areas of said pole pieces when said vane is in a definite position.

9. In an alternating current relay of the induction type, a movably mounted imperforate Vane of substantially semi-circular form having a flat Side, means for operating contacts at each of three positions of said vane and means for moving said vane comprising two separately magnetized cores having pole pieces, said cor-es being mounted on opposite sides of said vane and having their pole pieces symmetrically arranged with respect to said fiat side when said vane is in one of said three positions whereby the simultaneous magnetization of said cores by alternating currents displaced in phase relation will cause said vane to move to one of said three positions and the magnetization of either one of said cores alone will cause the vane to move to and remain in another of said three positions.

I 10. In an alternating current relay of the induction type, a movably mount-ed vane of electro-conductive material, and two separate electromagnetic means acting when simultaneously energized to produce a shifting magnetic field cuttinga portion of said vane for moving said vane in a given direction,

said vane being so formed as to be symmetrically disposed with respect to the magnetic fields produced by said electro-magnetic means only when the vane is in a predetermined position, and being formed to inter cept an increasing amount of said shifting magnetic field as the vane is moved in said given direction from said predetermined position, whereby the energization of one of said electro-magnetic means alone produces torque to move said vane to said predetermined position, and the simultaneous energization of said two electro-magnetic means produces a torque in said vane which increases as said vane is moved from said predetermined position.

11. In an alternating current relay of the induction type, a pivotally mounted vane of electroconductive material, said vane being of substantially semi-circular form having a straight edge and being biased to a predetermined neutral position by gravity, and two separately energized electro-magnetic means acting when simultaneously energized by alternating currents which are displaced in phase relation to produce a shifting magnetic field cutting a portion of said vane for moving said vane away from said neutral position, said vane and said electro-magnetic means being relatively positioned in such a manner that the straight edge of said vane is symmetrically disposed with respect to the magnetic field of said means only when said vane is in the neutral position, whereby the simultaneous energization of both of said electro-magnetic means produces a'torque in said vane which increases as said vane moves away from said neutral position, and the energization of one of said electro-magnetic means alone produces a torque in said vane for moving said vane to the neutral position.

In testimony whereof I aflix my signature WILLIAM D. HAILES. 

